Preheat oven to 350 degrees. Spray three 8-inch round cake pans with non-stick cooking spray and line the bottom of each pan with a circle of parchment paper.
Mix wet ingredients well, then add all the dry ingredients. Stir to combine until just mixed but smooth. Do not overmix.
Divide batter evenly between the three cake pans and bake for 20-25 minutes, or until a toothpick inserted into the middle of the cake comes out clean.
Allow the cakes to cool in the pans for 30 minutes, then drag a knife along the outside of the cake to make sure it isn’t sticking to the pan before removing the cake from the pan. Turn them out onto a wire rack to continue cooling.
Prepare the filling by combining white chocolate and heavy whipping cream in the top of a double boiler. Place water in the bottom of the double boiler and place over medium-low heat. Heat while stirring, until the white chocolate melts and the ganache becomes smooth.
Allow the ganache to cool until room temperature and then place in the refrigerator to chill. When it is cold, use a hand-held mixer or a stand mixer with the whisk attachment to whip the ganache.
To assemble the cake, place the first layer top side down on a cake plate. Top it with 1/3 of the whipped ganache. Repeat this process with the remaining layers, reserving a small amount of ganache to decorate the top of the cake. Scrape any ganache that is hanging over the sides around the cake using a scraper, which will lightly frost the sides. It is okay for the cake to show through on the sides.
To decorate the top, put some of the whipped ganache in an icing bag and pipe icing around the edges of the top layer.
Optional toppings to add to the top of the cake: walnuts, caramel, carrots, or strips of carrots.
Store in an airtight container at room temperature for 24 hours, then refrigerate any leftovers after that.
The calories shown are based on the cake being cut into 12 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**